Azo dye duplicating process



xaWLHEZF I copy sheet fof rea ies with'the essential dye fo A-ZO DYEDUPLICATING PROCESS Robert J. Klimkowski, Chicago, and Robert T.Florence, Park Ridge, 111., assignors to A. B. Dick Company, Niles,III., a corporation of Illinois No Drawing. Application April 13, 1953Serial No. 348,584

Claims. (Cl; 101+14'9A) This invention re1ate's to a copy' process,andjmere tion is made of a new and improved copy process of theduplicating type which eliminates many of the objecti'onable features"of the present spirit duplicating prdc ess. The improved process retainsthe simplicity and ease of operation ch'ar'acteristic of the spiritduplicating system' 'but eliminates its objectionable's'oilingcharacteristicsre'sulti'n'gfrorn' the use of a highly water soluble' dyein theicompositionQof the imaging material. In stead'of making use, of ahighly water and alcohol-soluble dye; the-imaging compositi'oii'of theinventions" described ,in' the' 'copending applications embodies adye-forming component which is substantially free o'f any dye'colorand'which is soluble in thefluid applied to the surfaceof'the-impression paper and is thereby leached for transferbfrom the'imaged masterto' the jmpressionpapen In the inipression paper, the dyeforrni'ng component com bines with other materials nec'essary forreaction to form the dyestuff in the full development of the image.

In the diazo dye system described, 'the-dia'iocoi'npound I may beprovided in the imaging material with which-the carbon sheet isformed'lan'd with which; the master is aged, while the coupler may besuppliedin the'fiuidor in the copy sheet for reactionwith the diazo' toform'the dyestuffs. In the alternative, the coupler may be pipvided asthe essential component in-tlie'ima'ging material 50 I r i the form ofan aromatic amine in a sufl icrently ac1d1fied and the diazo supplied inthe fluid:orin the impression aper for reaction Witli' nie coupler upontransfer from theimageti areas: of the master sheet to form the azoavenue"; Insteadthe c' apier andniej diazo, stabilized against re on'with: the couplen may beprpvided'i'n high concentifat'ionih' the imagingmaterial for reaction tofo'rin the aid dyestulf upontrerisferto the-impr'e'ssiofnf paper in'r espbnse to the adjustment of the pH:

with materials'coiita ned' a's a'riielinentin the" iluid wayof stillrnnn'er meeifieatieanie base of the'coupler or'thedi'a'zo adapted to esupplied in the' fluid or in the co mence n mfthe" image of:therha's'ter may be supplied in second t me tar wetting the impre sepane i b qu a'tft 6min h h image The" dirtines and staining chariicteristicsf of the spi duplicating process heretofore) employed has"been sub-[ stantially completely eliminated by the processes describedwithout loss of simplicityjorfle'ase of operation characteristic of thespirit duplicatingrsystcm as ithas been known up to the present date.[It i s belije production of multiple tes Patent 2,873,668 were? Fee-135 ice I the cost of the ingredients and to increase the stability of theingredients to light and heat so as to provide for the production ofuniform copies at less cost and without limitation as to the life of theim'agingmaterial or the conditions of storage of the various elements.

Improvements arealso believed possible by way of modification to enableuse of materials, which are less corrosive to duplicator parts andwhichv would enable a wider selection of compounds to. increase thecolor range of the copy and with particularattenti'on to the possibledevelopment of a. more intense and complete black, which is notavailable now in duplicating systems of the type described. Q

I It is an object of this inventiouto provide still further improvementsin a copy process of the type described, and it is a related object toproduce various compositions and elements for use in same. 1

Another object is to produce a new and improved com position for use inthe production of copy by a spirit duplicating process wherein theimaging material is free of dye color but in which the dye color isdeveloped fullyv in the impression paper in response to transfer ofdye-' forming components from the material forming the image in themaster upon contact.

- I It is-a related object to produce a new and improved imagingcomposition in the form'of an ink, ribbon or transfer sheet and toproduce a new and improved master, e ac h of which are substantiallyfree of dyecolor but which may be used'jn a conventional spiritduplicating 1 machine for the production of copy of good quality, and

it is a related object to produce a n-ew and improved duplicatingprocesswhich makes use of the same.

.Morespecifically, it is-an object of this invention to provide a newandimprovedduplicatingprocess of the compounds of a greater variety andlower cost may be:

used to produce copy in a greater range of colors, in-f cluding black,

the materials used in the'pracace of the. process-are more stable toheat and light and,

d 7 however; 7

that still further improvements are possible'in a"sys"ten1 therefore,capable of, use in the production of agreater number copies of a uniformuality With less effect from time; temperature or atmospheric conditionsand which are less corrosive to duplicator parts and materials is gonnathe'rewith;

It has been found that the aforementioned improvestems in the processespreviously described are achieved in a: system which makes use of adiazotizabl e amine in environment for reactionto cause analkalinitrite'to decompose into nitrous acid Whichreactsjwith the amineto' forma'diazo' compound. Thediazo formed is capable stre ms, with: acoupler; as before, to f'orm the azo' dyestuif. The coupler may beprovided in the form of the amine when present in excess of thatrequired to react with the nitrite, or it may be provided as anauxiliary compound qf the-type described in the co-pending applications.T heacidifying medium may constitute an acid in troduced as a separatecomponent, or it may be present in the form of anacidgroup; such: as a'sulfohic acid group, or as a part of" the amine saltl' As in the processof the co-pending applications which make use only of a diazoand'coupler, with or vithout' a base for pH adjustment, numerouspermutations are possible in the practice of this invention, a numberoff which will hereinafter be described; Since the dia zotizable amine.constitutes the more expensive of the elements, arid" since the aminesometimescauses.thedevelopment.

of background color, it is preferred to embodythe'ainine as one of theessential components in the imaging maasvaess 3 terial. It will beunderstood, however, that the diazotizable amine, or an amine salt, may,in the alternative, be incorporated as a component in the impressionpaper or may be applied as a component in the fluid applied to theimpression paper in advance of contact with the image master or even ina second fluid applied to the surface of the impression paper aftercontact with the image master. In either event, the amine is provided inthe impression paper to react with the latent image formed on thesurface of the impression paper to form the dyestutf.

When, as is preferred, the diazotizable amine is embodied as an elementin the imaging composition, the following combinations are possible:

A. With the amine salt in the imaging material, the nitrite, such assodium nitrite, may be incorporated (l) in the fluid with which thesurface of the impression paper is wet in advance of contact with theimaged master; (2) the sodium nitrite may be embodied in the impressionpaper as by a prior coating process or by providing the nitrite in theslurry from which the impression paper is prepared; or (3) the sodiumnitrite may be applied from a second solution with which the surface ofthe impression paper is wet after contact with the imaged master.

B. With the amine salt and acid in the imaging ma terial, thedisposition of the nitrite may be in either of the elements (1), (2), or(3) of A above.

C- Both the amine salt and the nitrite may be compounded as componentsof the imaging material and the acid for reaction with the nitriteincorporated in (1) the fluid, (2) the impression paper, or (3) in asecond fluid applied to the impression paper after contact with theimaged master.

When a separate coupler is used, it may be incorporated either in theimaging material or in the fluid, or in a second fluid in each of thecombinations (A), (B) and (C) previously described.-

It will be 'apparentthat a number of permutations are also possible withthe nitrite in the imaging material and the amine, coupler and acidsarranged together or separately in the other elements, including thefluid with which the impression paper is wet in advance of contact withthe imaged master, or a second fluid applied to the surface oftheimpression paper after contact with the imaged master. It is onlynecessary that a separation between the-respective elements bemaintained as between the acid and the nitrite so as to avoid thepremature formation -.of nitrous acid used to formthe diazo of theamine, and it is also essential in governing the arrangement ofelementsin accordance with the practice of this invention to make use of onlythose components in the imaging material which are soluble in the fluidapplied to the; surface of the impression paper so as to effect thedesired leaching of the dye-forming components from the image of themaster to the impression paper for reaction to form the dyestutf.

The following will illustrate the practice of this invention in acombination wherein the imaging material is formulated to contain theamine salt and the fluid used therewith in the production of brown copycontains the nitrite:

EXAMPLE 1 Imaging material for use in the production of a transfercarbon In the preparation of the transfer carbon, the materials arecombined together to form a hot melt at a tempera ture of between 80 to100 C. as by a milling machine '4 using heated rolls, and then coatedonto a web of paper to form coating weights of about 15 to 25 lbs; per3,000 sq. ft. of surface area. The coating formed constitutes a surfacecoating which is weakly bonded to the backing sheet so as to enable easydisplacement onto the surface of the master in response to appliedforce.

EXAMPLE 2 Fluid composition for use with the imaging composition ofExample 1 86.0% by weight methanol 10.0% by weight water 4.0% by weightsodium nitrite In use, the coated surface of the transfer carbonproduced with the composition of Example 1 is placed in contactingrelation with the surface of a master sheet. The image is formed on themaster sheet by transfer of coating from the carbon in response toapplied force as by a die impression, typewriter key, or by a stylus.

The master having the image in reverse is then mounted in a standardspirit duplicating machine and the impression paper is fed intocontacting relation with the imaged surface of the master after thesurface of the impression paper has been wet, as by means of a wick or awiper blade, with the fluid of Example 2.- Upon contact, the solventportion of the fluid leaches some of the amine salt from the imagedareas of the master. for transfer to the impression paper. The acidicsalt causes the nitrite in the fluid on the impression paper to revertto nitrous acid, which reacts with the amine portion to form a diazocompound. The diazo couples with the remainder of the amine to form anazo dye to produce copy in the im-.

pression paper. These reactions occur substantially'simultaneously sothat the formation of a dyestulf becomes apparent by the time theimpression paper passes from between the printing couple of theduplicating machine,-.

but the intensity of the dyestutf increases upon standing, especially ifthe papers are stacked in a manner to hold in some of the fluidwhichiunctions as an ionizingmedium to continue the reaction.

The following example illustrates the combination when the imagingmaterial contains both the amine and acid as separate ingredients forreaction with a nitrite contained ina fluid as in Example 2, or in asecond fluid:

EXAMPLE 3 A transfer carbon is formed as previously described from a hotmelt of the above composition. When used in combination with the fluidof Example 2 to produce copy on the impression paper, a blue dyestuif isformed. In this system, the acid and the amine salt, soluble in alcoholand water, are leached from the imaged master for transfer to theimpression paper upon contact with the surface of the impression paperwetted with the fluid of Example 2. There the acid reduces the nitriteto nitrous acid. The nitrous acid reacts with the amine salt to form adiazo and thenthe diazo couples with the remainder of the amine to formthe blue azo dyestuif.

The following will illustrate the combination wherein a separate coupleris incorporated with the amine in the form of an acid salt" in theimaging material and the nitrite is provided either in the fluid, in'theimpression paper, or in a second fluid:

EXAMPLE 4 12.0% by weight carnauba Wax 17.0% by weight microcrystallinewax 14.5% by weight lactic acid 13.0% by weight heavy mineral oil 1.5%by weight sodium oleate 21.0% by weight 2,4 diaminotoluene I t 21.0% byweight paranitroaniline hydrochloride A transfer carbon is formed aspreviously described, using a hot melt of the composition of Example 4.When impression paper having its surface wet with the fluid ofComposition 2 is brought into surface contact with av master imaged withthe composition of Example 4, the 2,4 diamino toluene andparanitroaniline hydrochloride are leached from theimage to theimpression paper for reaction to transpose the nitrite into nitrous acidwhich reacts with the amine to produce a diazo. The diazo reacts withthe coupler to produce the azo dyestuff.

The following are further modifications of the system described in whichvarious combinations of amine salts and acid salts are formulated intothe imaging material:

EXAMPLE 5 12.0% by weight carnauba wax- 17.0% by weight Cardis 262 wax14.5% by weight heavy mineral oil 130% by weight light mineral oil 1.5by weight sodium oleate v I v 42.0% by weight triaminotoluenetrihydrochloride EXAMPLE 6 12.0% by weight carnauba wax 17.0% by weightCardis 262 wax 14.5% by weight heavy mineral oil 13.0% by weight lightmineral oil 1.5% by weight sodium oleate o 15.0% by weightm-phenylenediamine dihydrochloride' 27.0% .by weightp-amino-N,N-diethylaniline hydrochloride 1 V EXAMPLE 7 12.0% by weightcarnauba wax 17.0% by Weight Cardis 2 62 wax 14.5% by weight heavymineral oil 13.0% 'by weight light mineral oil 1.5 by weightsodiumoleate v i 42.0% by weight p-amino-N,N diethylaniline hydrochlo-.rid'e EXAMPLE 8 12.0%"by weightcarna'iiba wax 170% by weight Cardis 262wax 1415 by weight heavy mineral oil 13.0% by weight lightrnineral oil1.5 'by weight sodium oleate H r 15.0% by weight m-phenylenediaminedihydrochloride 27.0% by weight benzidinedihydrochloride EXAMPLE 9-12.0% by weight carnauba wax 17.0% "by weight Cardis 262 w'ax 14.5% byweight heavy mineral oil 13.0% by weight light mineral oil 1.5 byweightsodium oleate I 20.0% by weightp-aminodiphenylamine hydrochloride 22:0by weight rheny1-s-n1sth r5- yrazo1ene in'g; material embodying featuresof this -inveritio1i,-illus-" "75 trat'io'n was made of formulations foruse in the preparation of a transfer carbon which is the means mostoften used for imaging a master. Use may also be made of other waxessuch as paraflin wax, ozokerite wax, [and other natural, petroleum, coaltar or vegetable waxes, or synthetic waxes, alone or in combination withsoftening or fluidizing agents such as mineral oils, vegetable oils,fatty acids, fatty acid esters, hydrogenated rosin, plasticizers, andthe like, in various amounts and proportions, depending on whether useis to be made to produce a transfer carbon or whether a more fluidcomposition is desired for use in a typing ribbon, or an ink forapplication by a writing pen, stylus, or the like, to image the .master.

As will be evident from the examples, the amines,

' amine saltsr or amine acid salts, may 'be selected of a large numberof commercially available diazotiz able aromatic amine compounds. Whenincorporated as a component of the imaging material, it is importantthat the diazotizable amine components and the other com ponentsentering into the reaction to forni the dyestufi be soluble in the fluidcomposition with which the impression paper is wet and the amines shouldbe, reactive with nitrous acid to form a dye compound capable of.

reaction with the coupler to form vthe dyestuff.

When the coupler is applied as a component of the imaging material,separate and apart from the amine, it is preferred to make use of acoupler in the form of an organic compound such as an aromatic amine ofthe type aniline "or a substituted aniline such as dimethylaniline orWith the fluid of Example 2, brown copy is produced phenolic cornpoundssuch as phenol, resorcinol, phloroglucinol,"2,'3 dihydr'oxy'naphthol'sulfonie acids, or thio compounds such as thiobarbituric acid,or cyano can pounds such as cyanoaeetamide, or pyrazolone, orderivatives thereof. i t I While dilute solutions" of inorganic acidsmay be' used as'the acidic medium when incorporated infafluid or,

when incorporated as a component in' the, imaging rn'at'e rial separateand apart: from the nitrite, it preferred make use of organic acids'ofthe type stearic acid, lactic acid, formic acid, propionic acid, benzoicacid, and the like. The amount of acid is unimportant, since it is onlynecessary to have sufiicient' acid present to cause theforrnation ofnitrous acid uponreaction with alkali metal nitrite. V a

For thepr'oper production of a maximum'number or copies, it is desirableto incorporate as high concentra-f non of the diazotizable amine orother components of the dye'as is'po'ss'i ble int-o the imagingcomposition consi-stent'withthe ability of the composition to embodythe" characteristics necessary for imaging purposes or for themanufacture of a suitable transfer carbon. Generally,- it is desirableto have a concentration of the dye-forming component presentin amountsgreater than 20%; by'

Weight of the imaging composition and concentratibris up "-to by weightcan'- be tolerated without interfering with the characteristics of thematerial for the purpose for which it was intended; Where thedye-forming components contained in- .the imaging material or thecomposition vfor forming the coating on the transfer carbon comprise twocomponents such as a diazotizable amine,

a diazotizable amine and coupler, or a diazotiz'able' amine and nitrite,the concentrations are preferably reduced to an amount greater than 20%by weight but less than an amount capable of forminga total of 75% byweight of the imaging composition. In" a diazotiza ble amine-couplersystem itis preferable to have more amine than coupler such as in aratio of l- -3 to 1. Lesser concentrationsof the nitrites' are required,it being suflicient when the amount in the imaging materialis within therange of from 1-15% by weight. 7 The following examples are illustrativeof other permutations which may be made with respect to the,distrrbu'tro'n of the: Various components in the compositions used-inthe pr'actice'of the duplicating process.

For example; the following willi'illust'rat e the system aa'raees.

wherein an amine salt or an amine-salt and a nitrite are formulated tobe contained in the imaging material while the fluid contains thesolvent or the acidic medium necessary under certain circumstances forconversion of the nitrite to nitrous acid.

EXAMPLE 10 Carbon-coating composition by weight carnauba wax by weightmicrocrystalline wax 14.5% by weight heavy mineral oil 13.5% by weightlight mineral oil 1.5% by weight sodium oleate 5.0% by weight sodiumnitrite 37.0% by weight m-phenylenediamine dihydrochloride EXAMPLE 11Fluid 90% by weight methanol 10% by weight water EXAMPLE 12 45.0% byweight 1amino-2-naphthol 4-sulfonic acid 15.0% by weight sodium nitrite5.0% by weight carnauba wax H 10.0% by weight oxidized microcrystallinewax 25.0% by weight light mineral oil EXAMPLE 13 Fluid composition foruse with the imaging composition of Example 12 r 4.0% by weightl.-phenyl-3-rnethyl5-pyrazolone 2.0% by weight lactic acid 94.0% byweight methanol With the system of Examples 12 and 13 used in a copyprocess of'the type previously described, a red dyestuft forming thecopy in the impression paper will result.

Another system similar to that of Examples 12 and 13 wherein the aminesalt and nitrite are contained in the imaging material and the acidcontained in the fluid, is illustrated by the following furtherexamples:

EXAMPLE 14 Imaging composition 25.0% by weight 1 amino, Z-naphthol,4-sulfonic acid 20.0% by weight phloroglucinol 15.0% by weight sodiumnitrite 5.0% by weight carnauba wax 10.0% by weight oxidizedmicrocrystalline wax 25.0% by weight light mineral oil EXAMPLE 15 Fluidcomposition for use with Example 14 3.0% by weight lactic acid 7.0% byweight water 90.0% by weight methanol When the impression paper havingits surface wet with the fluid composition of Example 15 is brought intosurface contact with the master imaged with the composition of Example14, the dye-forming components transfer from the imaged areas of themaster to the impression paper, where the lactic acid causes the sodiumnitrite to form into nitrous acid. This forms the diaz0 compound of thel-amino, Z-naphthol, 4-sulfonic acid,

which then reacts with the phloroglucinol coupler to form the azodyestuff.

' The following example illustrates the practice of this invention whenthe amine salts and coupler are contained in the imaging material andthe sodium nitrite is contained, as is often desirable, in theimpression paper while the fluid merely constitutes a solvent for theamine salt and coupler to effect transfer from the imaged master to theimpression paper for reaction in the manner previously described.

EXAMPLE 16 Imaging composition 12.0% by weight carnauba wax 17.0% byweight rnicrocrystalline wax 14.5 by weight heavy mineral oil 13.0% byweight light mineral oil 1.5 by weight sodium oleate 27.0% by weightp-amino-N,N-dimethylaniline monohydrochloride 15.0% by weightm-phenylenediamine dihydrochloride EXAMPLE 17 Composition for coatingthe impression paper to introduce sodium nitrite 86.0% by weightmethanol 10.0% by weight water 4.0% by weight sodium nitrite In the useof the compositions of Examples 16 and 17.,

the impression paper is first coated with the fluidsystem of Example 18and then allowed to dry to set the sodium nitrite in the surface portionof the paper. In the production of copy, paper which has been treatedwith the.

composition of Example 17 is wet with methanol before being brought incontact with. the master imaged with the composition of Example 16. Themethanol causes the amine salts and coupler to be leached for transferfrom the imaged master to the impression paper, where reaction takesplace to form nitrous acid from sodium nitrite, followed bydiazotization of the amine and coupler to form the azo dyestufif.

The following will illustrate the practice of this in- ,vention whereinthe nitrite is contained as the dye-forming component in the imagingmaterial and the amine salt is contained as a component in the fluid.

EXAMPLE 18 12.0% by weight carnauba wax 17.0% by weight microcrystallinewax 14.5 by weight heavy mineral oil 13.0% by weight light mineral oil1.5% by weight sodium oleate 42.0% by weight sodium nitrite EXAMPLE 19Fluid for use with composition of Example 18 5.0% by weightmethyl-p-phenylenediamine dihydrochloride 10.0% by weight water 85.0% byweight methyl alcohol With the system of Examples 18 and 19, intenseblack copy will be produced. a

When a two-fluid system is used to produce copy, the essential componentfor completion of the reaction may be incorporated in a second fluidapplied to the surface 'of the impression paper after the latter hasbeen in contact with the imaged master and contains a latent image,

est-sees formed fliereim' For example, the sodium nitrite of Example 2may be; deleted from the solution and incorporated in a correspondingconcentration in a separate aqueous system. In use, the masterimaged-with the compositions of either Examplesl and 3' to 9 is firstcontacted with the impression paper having-its surface wet with asolvent such as methanol and water. The amine salts, and acid whenpresent, and coupler when present; will be extracted by the solvent fortransfer from the imaged master to the impression medium to form alatent image therein. When the surface of the impression paper issubsequently wet with a solution containing the nitrite, the acid willfunction to convert the nitrite to nitrous acid which will react thenwith the amine to form the diazo, which then couples to form therespective azo dyestuff in the development of copy. I

The acid may be separated from'the fluid of compositions 13 and 14 forincorporation in a second fluid as described for use in a two-fluidsystem with a master imaged with the composition of either Example 12 orExample 14, respectively.

Itw'ill be apparent from the description that the process describedherein provides for further improvements in a duplicating system whichhas the simplicity of the present' spirit duplicating process withoutthe handicap of dye transfer and stain during the manufacture of imagingmaterial or in the handling thereof to produce a transfer ribbon or atransfer carbon or in the use thereof in the preparation of an imagedmaster and the use thereof to produce copies. A system of the typedescribed enables the production of a greater range of colors in theformation of copy and it permits the formation of copy from a dyestuffwhich is relatively insoluble and, therefore, incapable of beingdestroyed in response to moisture or high humidity. The elimination of adiazo as a component of the described system also permits theutilization of lower cost of materials in the copy process and theproduction of elements for use in the multiple copy process which aresubstantially free of color and substantially devoid of the developmentof any background color when incorporated into the impression paper.

It will be understood that a system of the type described may beemployed when the essential dye-forming components in the imagingmaterial are substantially soluble in water in the copy processheretofore referred to as the process of hectographic duplication.

It will be understood that changes may be made in the details ofconstruction, formulation and application without departing from thespirit of the invention, especially as defined inthe following claims.

We claim? 1. The method of producing copy with a master imaged with acomposition containing an acidic medium and an amine compound capable ofdiazotizatiomcomprising the steps of wetting the surface of animpression paper with a fluid containing a solvent for the diazotizableamine and acid and also containing a nitrite and a coupler, andcontacting the imaged surface of the master with the wetted surface ofthe impression paper, whereby some of the diazotiza'ble amine compoundtransfers from the imaged portion of the master to the impression paperfor reaction to form the azo dyestuif.

2. The method of producing copy with a master imaged with a compositioncontaining an alkali metal nitrite and a diazotizable amine compoundpresent in a concentration ranging from -75% by weight of thecomposition and capable of coupling reaction to form an azo dyestutf,comprising the steps of wetting the surface of an impression paper witha fluid containing a solvent for the amine compound and the nitrite andalso containing an acid and coupler for reaction to form nitrous acid ofthe nitrite, and contacting the imaged surface of the master with' thewetted surface of the impression paper, whereby some of the diazotizableamine compound and nitrite transfers from the imaged portion of themaster to the impression.

paper for reaction to form the azo dyestuif.

3. The method of producing copy with a 'master imaged with a compositioncontaining a diazotizable amine compound present in an amount within therange of 20-75%; by weight of the composition and an acidic medium forreaction to form nitrous acid of a metal nitrite, comprising the stepsof wetting the surface of an impressionpaperwith a fluid containing asolvent for the diazotiza'ble amine compound and the acidic medium andwhich also contains the diazotized amine, comprising the steps ofwetting the surface of an impression paper with a fluid containing a'solvent for the diazotizable amine and coupler and which also contains anitrite and anacidic medium for reaction" Withthe diazotizableaminecompound in'the presence of nitrous acid, and contacting the imagedsurfa'ce of the master with the wetted surface of the impressionfp'aper,whereby some of the diazotizable amine and coupler is" leached fortransfer from the imaged portion of the master to the impression paperand reacts with the nitrite to form an azo dyestuff.

5. The method of producing copy with a master imaged with a compositioncontaining a diazotizable amine compound capable of reaction with acoupler to form an azo dyestuif, a coupler and an acidic medium,comprising the steps of wetting the surface of an impression paper witha fluid containing a solvent for the diazotizable amine, coupler andacidic medium and which also contains a nitrite, and contacting theimaged surface of the master with the wetted surface of the impressionpaper, whereby some of each of the dye-forming components in the imagedportion of the master are leached for transfer to the impression paperfor reaction to form the dyestuif.

6. The method of producing copy with a master imaged with a compositioncontaining an alkali metal nitrite present in a connection within therange of 115% by weight of the composition, comprising the steps ofwetting the surface of an impression paper with a fluid containing asolvent for the nitrite and which also contains an acidic medium and adiazotizable amine salt capable also of acting as a coupler to form anazo dyestuif, contacting the image surface of the master with the wettedsurface of the impression paper, whereby some of the nitrite is leachedfor transfer from the imaged portion of the master to the impressionpaper for reaction to form an azo dyestufli.

7. The method of producing copy with a master imaged with a compositioncontaining an alkali metal nitrite present in a concentration within therange of 1-15% by weight, comprising the steps of wetting the surface ofan impression paper with a fluid containing a solvent for the nitriteand also containing a diazotizable amine compound, a coupler, and anacid, and contacting the imaged surface of the master with the wettedsurface of the impression paper, whereby some of the nitrite is leachedfor transfer from the imaged portion of the master to the impressionpaper for reaction to form the dyestuif.

8. The method of producing copy with a master imaged with a compositioncontaining an alkali metal nitrite and a coupler capable of reactionwith a diazo compound to form an azo dyestufr", comprising the steps ofwetting the surface of an impression paper with a fluid containing asolvent for the nitrite and coupler and which also contains adiazotiza'ble amine compound and an acid, and contacting the imagedsurface of the master with the wetted surface of the copy sheet, wherebysome of the nitrite and coupler is leached for transfer from the imagedportion of the master to the impression paper for reaction to form anazo dyestuif.

. 9. The method of producing copy with a master imaged with acomposition containing an acidic medium and an amine compound capable ofdiazotization, comprising the steps of contacting the imaged surface ofthe master with an impression paper, wetting the surface of theimpression paper, prior to contact with the imaged master and againsubsequent to contact with the imaged master, with fluids, the first ofwhich contains a solvent for the diazotizable amine compound and theacidic medium and the second of which contains a nitrite and a couplerfor reaction with the diazotizable amine compound, to form an azodyestutt.

10. The method of producing copy with a master imaged with a compositioncontaining an alkali metal nitrite and a diazotizable amine compoundpresent in an amount within the range of 20-75% by weight of thecomposition and capable of coupling reaction to form an azo dyestuif,comprising the steps of contacting the imaged surface ofthe master withan impression paper, and wetting the surface of the impression paperbefore and after contact with the imaged master with fluids, the firstof which contains a solvent for the diazotizable amine compound andnitrite, and the second of which contains an acid and a coupler.

References Cited'in the file of this patent UNITED STATES PATENTS831,582 Thorpe Sept. 25, 1906 1,514,222 Murray Nov. 4, 1924 1,571,320Clavel Feb. 2, 1926 1,646,296 Kircheisen Oct. 18, 1927 1,825,342 Dreyfuset a1 Sept. 29, 1931 2,146,976 Neidich Feb. 14, 1939' 2,217,349 NeidichOct. 8, 1940 2,364,359 Kienle et al Dec. 5, 1944 2,526,995 Clark Oct.24, 1950 2,554,909 Holik May 29, 1951 2,596,756 Yutzy et a1 May 13, 19522,634,677 Klimkowski et a1. Apr. 14, 1953 FOREIGN PATENTS 193,646 GreatBritain Mar. 1, 1923 OTHER REFERENCES Diserens: The Chemical Technologyof Printing and Dyeing, 1948, Reinhold Pub. Co., N. Y. Only pp. 266 to269.

Saunders: The Armatic Diazo Compounds, 2nd edition, 1949, Arnold & Co.,London. Only pp. 95, 96 and 97.

1. THE METHOD OF PRODUCING COPY WITH A MASTER IMAGED WITH A COMPOSITIONCONTAINING AN ACIDIC MEDIUM AND AN AMINE COMPOUND CAPABLE OFDIAZOTIZATION, COMPRISING THE STEPS OF WETTING THE SURFACE OF ANIMPRESSION PAPER WITH A FLUID CONTAINING A SOLVENT FOR THE DIAZITIZABLEAMINE AND ACID AND ALSO CONTAINING A NITRITE AND A COUPLER, ANDCONTRACTING THE IMAGE SURFACE OF THE MASTER WITH THE WETTED SURFACE OFTHE IMPRESSION PAPER, WHEREBY SOME OF THE DIAZOTIZABLE AMINE COMPOUNDTRANSFERS FROM THE IMAGED PORTION OF THE MASTER TO THE IMPRESSION PAPERFOR REACTION TO FORM THE AZO DYESTUFF.